Bunch of ChumpsG 15

Multiverse Madness mode is similar to Firefight mode in Halo or Horde mode in Gears of War. What worked for me was to play on the Space Station map and stick to the starting area (in the room near the Joe special item with the health pack special item in it). this way I could force the enemy waves to funnel themselves to me through the room's only enterance.

I played as Quagmire and once I had enough cash I purcased the acid sprayer and watched my enemies melt away. I also purchased landmines and placed them between waves.

After 15 waves you'll get the achievement. Once you have completed all 30 waves, you'll get Cartoon Apocalypse..

* BraveZach suggests that for a faster reload, stand by the store portal and press X to open it then B to cancel. *